Manufacturing method for sulfonic acid group-containing ether compound

ABSTRACT

The present invention provides a method for efficiently producing a sulfonic acid group-containing ether compound having a high purity and a good polymerizability while preventing production of a byproduct, and provides a sulfonic acid group-containing ether compound containing fewer impurities and having a good radical (co)polymerizability. 
     The present invention provides a method of producing a sulfonic acid group-containing ether compound by reacting a sulfurous acid compound with a compound represented by the formula (1): 
     
       
         
         
             
             
         
       
         
         
           
             wherein R 1  represents a single bond, a CH 2  group, or a CH 2 CH 2  group, and R 2  represents H, or a CH 3  group, 
             the method comprising the steps of: 
             adjusting pH of a reaction system to 5.5 or greater with use of an alkaline substance; and 
             adding the compound represented by the formula (1) to a reaction vessel containing the sulfurous acid compound.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of co-pending U.S. application Ser. No.13/063,563 filed on Mar. 11, 2011, which is a National Phase filingunder 35 U.S.C. §371 of PCT/JP2009/066008 filed on Sep. 14, 2009; andthis application claims priority to Application No. 2008-234243 filed inJapan on Sep. 12, 2008 under 35 U.S.C. §119; the entire contents of allare hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a method of producing a sulfonic acidgroup-containing ether compound. More specifically, the presentinvention relates to a method of producing a sulfonic acidgroup-containing ether compound comprising an unsaturated double bond, asulfonic acid (salt) group, and an ether bond.

BACKGROUND ART

A typical sulfonic acid group-containing ether compound comprising anunsaturated double bond, a sulfonic acid (salt) group, and an ether bondis 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt (hereinafter,also referred to as “HAPS”). A known method of producing HAPS comprisesthe steps of: reacting 1 mol of allyl alcohol with 1 mol ofepichlorohydrin at 100° C. for four hours; adding 1 mol of sodiumsulfite dissolved in water thereto; and reacting the mixture at 90° C.for five hours (Non-Patent Document 1). Each of Patent Documents 1 and 2discloses that HAPS is obtainable by reacting allyl glycidyl ether withsodium bisulfite added thereto. Additionally, a polymer comprisingsodium acrylate and a sulfonic acid group-containing ether compound suchas HAPS is known to be favorably used in a scale inhibitor, a corrosioninhibitor, and the like (see Patent Document 3, for example).

PRIOR ART DOCUMENT Patent Document

Patent Document 1: JP 2002-138115 A (see [0080])

Patent Document 2: JP H-11-302341 A (see [0023])

Patent Document 3: JP 2005-264190

Non-Patent Document

Non-Patent Document 1: Journal of Applied Polymer Science Vol. 79, pp21-28 (2001)

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

As above mentioned, each of Non-Patent Document 1, and Patent Documents1 and 2 discloses a method of producing HAPS, and Patent Document 3discloses an application of the polymer using HAPS. However, in theconventional method, the yield rate of HAPS is poor and a lot ofbyproducts such as 3-allyloxy-1,2-dihydroxypropane are produced,resulting in problems that the polymerizability of HAPS is lowered andthe performance of the obtained polymer is insufficient when HAPS isused as a polymer material. The sulfonic acid group-containing ethercompound having a lot of impurities hardly has fine polymerizability.Therefore, in order to produce a (co)polymer comprising a sulfonic acidgroup-containing ether compound as a raw material, it has been needed toselect a technique such as polymerization under severe conditions toreduce residual monomers, use of a large amount of a polymerizationinitiator, and limitation on the monomer composition ratio. Accordingly,there has been still a room for improvement in facilitation ofproduction of a sulfonic acid group-containing ether compound having ahigh purity and a good polymerizability. In addition, there has beenstill a room for production of a sulfonic acid group-containing ethercompound having a higher purity and a better polymerizability.

Considering the above-described state of the art, the present inventionhas been devised. The object of the present invention is to provide amethod for efficiently producing a sulfonic acid group-containing ethercompound having a high purity and a good polymerizability whilepreventing production of a byproduct, and to provide a sulfonic acidgroup-containing ether compound containing fewer impurities and having agood radical (co)polymerizability.

Means for Solving the Problems

The present inventors have examined various methods of producing asulfonic acid group-containing ether compound such as3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt (HAPS). Then,the present inventors have found out that a specific reaction modeinhibits a secondary reaction and allows a high-yield and easyproduction of a sulfonic acid group-containing ether compound having ahigh purity and fewer byproducts. The specific reaction mode refers to amode in which a reaction between a sulfurous acid compound as a rawmaterial and a specific ether compound (compound represented by formula(1)) such as allyl glycidyl ether is carried out by adding the specificether compound to the sulfurous acid compound. In addition, the presentinventors have found out that pH adjustment of a reaction systemincreases that effect. Thereby, the present inventors solved the aboveproblems. Further, a composition containing the sulfonic acidgroup-containing ether compound obtainable by the method has fewimpurities and highly-pure sulfonic acid group-containing compound.Therefore, the composition has an excellent polymerizability so as toproduce a polymer excellent in scale inhibition ability and cleaningcapability when used as a polymer material. The polymer is suitably usedin chemicals for water treatment, detergent builders, detergentcompositions, dispersants, detergents and the like. Thereby, the presentinvention has been completed.

In the present invention, reaction carried out by adding a specificether compound to a sulfurous acid compound is a necessary step. Thisallows high-yield and easy production of a sulfonic acidgroup-containing ether compound having a high purity and fewerbyproducts. Accordingly, the present inventors found out that the effectis exerted because of a specific addition manner of raw materials. Alsoin this regard, the present invention has an important technicalmeaning.

The present invention provides a method of producing a sulfonic acidgroup-containing ether compound by reacting a sulfurous acid compoundwith a compound represented by the formula (1):

wherein R¹ represents a single bond, a CH₂ group, or a CH₂CH₂ group, andR² represents H, or a CH₃ group,

the method comprising the steps of:

adjusting pH of a reaction system to 5.5 or greater with use of analkaline substance; and

adding the compound represented by the formula (1) to a reaction vesselcontaining the sulfurous acid compound.

The present invention also provides a composition comprising sulfonicacid group-containing ether compound represented by the formula (2),

wherein

the composition has pH of 10 or greater, and

the composition comprises, with respect to 100 mol % of the compoundrepresented by the formula (2), less than 10 mol % of a compoundrepresented by the formula (3):

wherein R¹ represents a single bond, a CH₂ group, or a CH₂CH₂ group, R²represents H, or a CH₃ group, X and Y may be the same as or differentfrom each other and each represent a hydroxy group or a sulfonic acid(salt) group, and at least one of X and Y is a sulfonic acid (salt)group.

Hereinafter, the present invention is described in detail.

<Method of Producing a Sulfonic Acid Group-Containing Ether Compound>

The method of producing a sulfonic acid group-containing ether compoundof the present invention is a method for reacting the compoundrepresented by the formula (1) with a sulfurous acid compound. Here, itis to be noted that the reaction between the compound represented by theformula (1) and a sulfurous acid compound is also simply referred to as“reaction”.

In the compound represented by the formula (1), R¹ represents a singlebond, a CH₂ group, or a CH₂CH₂ group. Among these, R¹ preferablyrepresents a CH₂ group. Namely, the compound represented by the formula(1) is preferably a compound represented by the formula (1) in which R¹is a CH₂ group. In the case where R¹ is a CH₂ group, the scaleinhibition ability is further improved in the polymer obtained bypolymerizing a sulfonic acid group-containing ether compound that isobtainable by using the above compound as a raw material. From thestandpoint of further improving the scale inhibition ability of thepolymer, (meth)allylglycidyl ether is particularly preferable as thecompound represented by the formula (1).

Preferable examples of the sulfurous acid compound include sulfurousacid, hydrogen sulfite, dithionous acid, metabisulfurous acid, and saltsof these. The sulfurous acid compound may be used in a form of acid(i.e. sulfurous acid and the like). However, from the standpoint ofhandling ease and improvement in the yield rate, it is preferably addedin a form of salt. Namely, the sulfurous acid compound is preferablysalt. Further, the sulfurous acid compound more preferably comprises atleast one kind of salt selected from the group consisting of sulfitesalts, bisulfite salts, dithionite salts, and metabisulfite salts. Inparticular, the sulfurous acid compound preferably comprises a loweroxide, such as sodium bisulfite, potassium bisulfite, sodium dithionite,potassium dithionite, sodium metabisulfite, and potassium metabisulfite,or a salt thereof. From the standpoint of the cost efficiency andimprovement in the yield rate, the sulfurous acid compound morepreferably comprises bisulfite salts and metabisulfite salts, andparticularly preferably comprises sodium bisulfite and sodiummetabisulfite.

Examples of the salts include metal salts, ammonium salts, and organicamine salts. More specifically, examples of the salts include: alkalimetal salts such as sodium salt and potassium salt; alkaline earth metalsalts such as magnesium salt, calcium salt, strontium salt, and bariumsalt; salts such as aluminum salt and iron salt; ammonium salt;alkanolamine salts such as monoethanolamine salt, diethanolamine salt,and triethanolamine salt; alkylamine salts such as monoethylamine salt,diethylamine salt, and triethylamine salt; and polyamine salts such asethylendiamine salt and triethylenediamine salt.

The method comprises the steps of: adjusting pH of a reaction system to5.5 or greater with use of an alkaline substance (hereinafter, alsoreferred to as “pH adjustment step”); and adding the compoundrepresented by the formula (1) to a reaction vessel containing thesulfurous acid compound (hereinafter, also referred to as “additionstep”). Here, the method may further comprise another step that may becarried out in a common method, as long as it does not adversely affectthe effect of the present invention.

In the pH adjustment step, pH of a reaction system is adjusted to 5.5 orgreater with use of an alkaline substance. At that time, the reactionsystem (which refers to the inside of the reaction vessel, morepreferably, a solution in the reaction vessel) preferably comprises anaqueous solution of a sulfurous acid compound and an alkaline substance.Namely, it is preferable to adjust pH of the reaction system by mixingthe alkaline substance and the aqueous solution of a sulfurous acidcompound. For example, such adjustment of pH to 5.5 or greater iscarried out by (1) adding an aqueous solution of a sulfurous acidcompound to a reaction vessel containing an alkaline substance andmixing them, (2) adding an alkaline substance to a reaction vesselcontaining an aqueous solution of a sulfurous acid compound, or (3)simultaneously adding an aqueous solution of a sulfurous acid compoundand an alkaline substance to a reaction vessel and mixing them. Any ofthe above methods can be employed. In particular, from the standpoint ofinhibiting generation of sulfurous acid gas, the adjustment (1) (pH isadjusted to 5.5 or greater by adding an aqueous solution of a sulfurousacid compound to a reaction vessel containing an alkaline substance andmixing them) is most preferable. In the adjustment (1), only a part ofentire the alkaline substance needed to adjust pH to 5.5 or greater maybe added prior to the addition of the aqueous solution of a sulfurousacid compound and the rest of the alkaline substance may be addedtogether with the aqueous solution of a sulfurous acid compound.However, the entire alkaline substance is preferably added to thereaction vessel first.

The pH value of the reaction system adjusted in the pH adjustment stepis preferably 5.5 or greater. The pH value of less than 5.5 may lowerthe yield rate of the obtainable sulfonic acid group-containing ethercompound. The reason for this is not sufficiently clear yet. In thepresent invention, when a compound represented by the formula (1) isadded to the reaction vessel containing a sulfurous acid compound, thelow pH may cause discharge of the sulfurous acid gas outside the system.This presumably leads to the lowered yield rate of the obtainablesulfonic acid group-containing ether compound. The pH value of 5.5 orgreater leads to the effect of inhibiting generation of sulfurous acidgas. The pH value is more preferably 5.7 or greater, further preferably6.0 or greater, and particularly preferably 6.1 or greater. The upperlimit of the pH value is not particularly limited, and is preferably pH14 or lower.

The alkaline substance usable in the above adjustment is notparticularly limited, and examples thereof include hydroxides ofalkaline metals such as sodium hydroxide and potassium hydroxide,hydroxides of alkaline earth metals such as calcium hydroxide, ammonia,and amines. Each of these may be used alone or two or more of thesemaybe used in combination.

The amount of the alkaline substance is not particularly limited as longas it is an enough amount to adjust the pH of the reaction system to 5.5or greater. For example, the amount is preferably 0.1 mol or more, morepreferably 0.2 mol or more, and further preferably 0.3 mol or more, withrespect to 1 mol of the compound represented by the formula (1). Theamount is preferably 1 mol or less, more preferably 0.8 mol or less, andfurther preferably 0.36 mol or less.

In the addition step, a compound represented by the formula (1) is addedto a reaction vessel containing a sulfurous acid compound. Here, thetime point when both a compound represented by the formula (1) and asulfurous acid compound are added to a reaction vessel is referred to as“at the start of the reaction between a compound represented by theformula (1) and a sulfurous acid compound (also simply referred to as“at the start of the reaction”)”. The time point before the start of thereaction is referred to as “before the start of the reaction”.Accordingly, in the case where the addition is carried out after the pHadjustment, the pH adjustment is carried out “before the start of thereaction”.

In addition, “the reaction vessel” is a reaction vessel for carrying outa reaction between a compound represented by the formula (1) and asulfurous acid compound, and may be a tank-type or tube-type vessel.Further, “addition to a reaction vessel containing a sulfurous acidcompound” refers to a state where a sulfurous acid compound is presentin the reaction vessel when a compound represented by the formula (1) isadded to the vessel.

A part or the entire amount of the sulfurous acid compound is preferablyadded to the reaction vessel before the start of the reaction (initialplacement). For example, when the entire amount is 100 mol %, the amountof the initial placement is preferably 50 mol % or more, more preferably80 mol % or more, and further preferably 100 mol % (namely, the entireamount). Instead of the initial placement, it is also preferable to add80 mol % or more, more preferably 100 mol % of the sulfurous acidcompound in the entire amount of 100 mol % thereof to the vessel at avery early stage of the reaction (at a very early stage after the startof the reaction), for example, prior to the addition of 50 mol % or moreof the compound represented by the formula (1) in the entire amount of100 mol % thereof.

The amount of the sulfurous acid compound is preferably 0.9 mol or moreand 1.3 mol or less in the stoichiometric amount, with respect to 1 molof the compound represented by the formula (1). What is meant by “in thestoichiometric amount” is described in the following. For example, inthis case, an amount of 1 mol of sodium bisulfite used as a sulfurousacid compound reacts with 1 mol of the compound represented by theformula (1), and therefore, the amount of sodium bisulfite is preferably0.9 mol or more and 1.3 mol or less. In contrast, an amount of ½ mol ofsodium metabisulfite used as a sulfurous acid compound reacts with 1 molof the compound represented by the formula (1), and therefore, theamount of sodium metabisulfite is preferably 0.45 mol or more and 0.65mol or less, which is the ½ molar amount. When the amount is less than0.9 mol in the stoichiometric amount, there may be a case where thecompound represented by the formula (1) remaining unreacted increases ora lot of byproducts are produced. Further, when the amount is more than1.3 mol in the stoichiometric amount, the byproducts derived from thesulfurous acid compound may increases. The amount of the sulfurous acidcompound is more preferably 0.95 mol or more, further preferably 0.97mol or more in the stoichiometric amount, with respect to 1 mol of thecompound represented by the formula (1). Additionally, the amount of thesulfurous acid compound is more preferably 1.2 mol or less, and furtherpreferably 1.1 mol or less.

In the addition step, the compound represented by the formula (1) isadded to the reaction vessel containing the sulfurous acid compound.This inhibits a secondary reaction so as to improve the yield rate ofthe sulfonic acid group-containing ether compound.

A part of the compound represented by the formula (1), out of the totalamount thereof, maybe initially placed in the reaction vessel. However,from the standpoint of improving the yield rate of the sulfonic acidgroup-containing ether compound, 60 mol % or more, out of 100 mol % intotal, of the compound represented by the formula (1) is preferablyadded to the reaction vessel at the start of the reaction or later. Morepreferably 80 mol % or more, and further preferably 100 mol %, namely,the total amount of the compound is preferably added to the reactionvessel at the start of the reaction or later. Here, “at the start of thereaction or later” refers to the time point when the reaction starts orthe time point after the start of the reaction.

In the addition step, the compound represented by the formula (1) may beadded continuously or dividedly. Further, the compound represented bythe formula (1) may be added as it stands or after being diluted with asolvent in which the compound can be dissolved or dispersed. In the caseof using a solvent, it is preferable to use a solvent which is inert toa glycidyl group contained in the compound represented by the formula(1). The solvent may be appropriately selected in consideration of theability to dissolve the compound represented by the formula (1). Here,it is preferable not to use a solvent, from the standpoint of using thecomposition containing the obtained sulfonic acid group-containing ethercompound (composition commonly containing a reaction solvent andbyproducts, in addition to the sulfonic acid group-containing ethercompound) for various applications without additional treatment.

A particularly preferable mode of the addition step is a mode in whichthe compound represented by the formula (1) is dropped to the reactionvessel containing the sulfurous acid compound. The addition rate(preferably, the dropping rate) is preferably set to 0.01 to 10% bymass, out of the 100% by mass in total, of the compound represented bythe formula (1) per minute. The addition rate within this range allowsan efficient and sufficient reaction between the compound represented bythe formula (1) and the sulfurous acid compound. The addition rate(preferably, the dropping rate) is more preferably set to 0.5 to 5% bymass, out of the 100% by mass in total, of the compound represented bythe formula (1) per minute. In addition, the addition rate (preferably,the dropping rate) may be constant or may be changed during theaddition.

In the method, the addition step may be carried out after the pHadjustment step, or alternatively, the pH adjustment step and theaddition step may be carried out simultaneously. However, it ispreferable to carry out the addition step after the pH adjustment step.

Preferable modes of the method include the following modes A and B. Inparticular, the mode A is preferable.

-   Mode A: A part or the entire amount of an alkaline substance and the    sulfurous acid compound, out of the total amount thereof, are    initially placed in the reaction vessel. After the reaction system    (which refers to the inside of the reaction vessel, more preferably    the solution in the reaction vessel) is adjusted to have pH of 5.5    or greater, the compound represented by the formula (1) is added to    the reaction vessel.-   Mode B: Apart or the entire amount of the sulfurous acid compound is    initially placed in the reaction vessel. While the compound    represented by the formula (1) is added to the reaction vessel, the    reaction system is adjusted to have pH of 5.5 or greater.

In the case of the mode B, it is preferable to adjust the pH of thereaction system to 5.5 or greater as quickly as possible after the startof addition of the compound represented by the formula (1). When thereaction time at the pH of 5.5 or greater becomes longer in the entirereaction time, generation of sulfurous acid gas and production ofbyproducts are more efficiently reduced. For example, the reaction timeat a pH of 5.5 or greater is preferably 90% or more, more preferably 95%or more, and further preferably 100%, that is, the entire reaction time,in the entire reaction time.

In the method, the reaction between the compound represented by theformula (1) and the sulfurous acid compound may be carried out under theair atmosphere. However, the reaction under the inert atmosphere such asnitrogen atmosphere is preferable because coloring can be avoided. Inaddition, the reaction is commonly carried out in a solvent. Though thesolvent is not particularly limited, a solvent at least containing water(sole solvent of water or mixed solvent containing water and an organicsolvent) is preferable. The water in the entire solvent is preferably50% by mass or more, more preferably, 70% by mass or more, and mostpreferably 100% by mass. Namely, a sole solvent of water is mostpreferable. In addition, the solids concentration at the time ofreaction (solids concentration when the reaction is completed) ispreferably 20% by mass or more and 80% by mass or less.

The reaction is preferably carried out at a reaction temperature of 30°C. or higher and lower than 80° C. The reaction temperature lower than80° C. can reduce production of byproducts, and the reaction temperatureof 30° C. or higher is likely to improve the yield rate of the sulfonicacid group-containing ether compound as a target object. The reactiontemperature is more preferably 50° C. or higher and lower than 75° C.,and further preferably 58° C. or higher and lower than 68° C.

The most preferable mode is that the entire reaction step in the methodof the present invention is carried out at a reaction temperature withinthe above range. However, a mode is regarded to be preferable, in whichthe reaction is carried out at a reaction temperature within the aboverange for 30% or more of the entire reaction time. Moreover, a mode isregarded to be more preferable, in which the reaction is carried out ata reaction temperature within the above range for 50% or more of theentire reaction time.

In the method, after the addition step (step of adding the compoundrepresented by the formula (1)), a reaction may be further continued(such reaction may also be referred to as “post-reaction step”). Thisfurther improves the yield rate of the sulfonic acid group-containingether compound.

Addition of the compound represented by the formula (1) (namely, startof the addition step) starts the reaction between the sulfurous acidcompound and the compound represented by the formula (1), and therefore,“the entire reaction step” in the present description include theaddition step and the post-reaction step.

The sulfonic acid group-containing ether compound obtained in the methodis represented by the following formula (2):

wherein R1 represents a single bond, a CH₂ group, or a CH₂CH₂ group,

R² represents H, or a CH₃ group,

X and Y may be the same as or different from each other and eachrepresent a hydroxy group or a sulfonic acid (salt) group, and

at least one of X and Y is a sulfonic acid (salt) group.

In the formula (2), X and Y are groups derived from the sulfurous acidcompound and at least one of the two is a sulfonic acid (salt) group. Inparticular, it is preferable that one of X and Y is a sulfonic acid(salt) group and the other is a hydroxy group.

Here, the sulfonic acid (salt) group is a group represented by —SO₃Z (Zis a hydrogen atom, metal atom, ammonium group, or organic amine group).Preferable examples of the metal atom include alkali metals such assodium and potassium; alkali earth metals such as magnesium, calcium,strontium, and barium; aluminum and iron. Preferable examples of theorganic amine group include alkanolamine groups such as amonoethanolamine group, a diethanolamine group, and a triethanolaminegroup; alkylamine groups such as a monoethylamine group, a diethylaminegroup, and a triethylamine group; and polyamine groups such as anethylenediamine group and a triethylenediamine group. More preferableexamples of the sulfonic acid (salt) group include a sulfonic acidgroup, a lithium sulfonate group, a potassium sulfonate group, a sodiumsulfonate group, an ammonium sulfonate group, and a quaternary aminegroup of sulfonic acid.

In the formula (2), R¹ and R² are dependent on R¹ and R² in the compoundrepresented by the formula (1) as a raw material. As above described,the compound represented by the formula (1) is preferably a compound inwhich R¹ represents a CH₂ group, and therefore, the compound representedby the formula (2) is also preferably a compound in which R¹ representsa CH₂ group. In the case where R¹ is a CH₂ group, the scale inhibitionability of the polymer obtained by polymerizing the sulfonic acidgroup-containing ether compound is further improved.

The sulfonic acid group-containing ether compound is more preferably3-(meth)allyloxy-2-hydroxy-1-propane sodium sulfonate.

The method of the present invention enables efficient and easyproduction of a highly-pure sulfonic acid group-containing ethercompound (compound represented by the formula (2)) comprising fewerimpurities. The sulfonic acid group-containing ether compound obtainedin this manner has fewer impurities and is highly pure, and therefore,it has fine radical (co)polymerizability. Accordingly, when the compoundis used as a polymer material, a polymer excellent in scale inhibitionability can be obtained and is suitably used in chemicals for watertreatment, detergent builders, detergent compositions, dispersants,cleaners, and the like. Accordingly, one of the preferable embodimentsof the present invention include chemicals for water treatment,detergent builders, detergent compositions, dispersants, cleaners, andthe like, which contain polymers obtained by polymerizing the monomercomponent comprising the sulfonic acid group-containing ether compound.

<Composition Containing the Sulfonic Acid Group-Containing EtherCompound>

The composition containing the sulfonic acid group-containing ethercompound of the present invention comprises the sulfonic acidgroup-containing ether compound represented by the formula (2) and isobtainable by the above method of producing the sulfonic acidgroup-containing ether compound. Also from the standpoint of easyproduction, the composition is preferably produced by the above methodof producing the sulfonic acid group-containing ether compound.Therefore, one of the preferable embodiments of the present invention isan embodiment in which the composition containing the sulfonic acidgroup-containing ether compound of the present invention is obtained bythe above method. In this case, the composition containing the sulfonicacid group-containing ether compound necessarily comprises the sulfonicacid group-containing ether compound, and further comprise byproducts(for example, the compound represented by the formula (3)) and areaction solvent such as water in some cases. In addition, thecomposition containing the sulfonic acid group-containing ether compoundis preferably in the form of a solution, and more preferably in the formof an aqueous solution. The composition in the form of an aqueoussolution may be prepared by using a solvent containing at least water asa reaction solvent in the above method of producing the sulfonic acidgroup-containing ether compound.

The compound represented by the formula (3) tends to be secondarilyproduced in a reaction between the compound represented by the formula(1) and the sulfurous acid compound. The amount of the compoundrepresented by the formula (3) in the composition containing thesulfonic acid group-containing ether compound is preferably less than 10mol % with respect to 100 mol % of the compound represented by theformula (2). In the present invention, employment of the above method ofproducing the sulfonic acid group-containing ether compound allowssufficient reduction of the amount of the compound represented by theformula (3) as a byproduct in the composition containing the sulfonicacid group-containing ether compound. This leads to the higher purity ofthe sulfonic acid group-containing ether compound. Accordingly, whensuch a composition containing sulfonic acid group-containing ethercompound is used as a polymer material, it is possible to obtain apolymer particularly excellent in scale inhibition ability. From thestandpoint of the performance of the polymer and the polymerizability ofthe sulfonic acid group-containing ether compound, the amount of thecompound represented by the formula (3) is preferably less than 10 mol%, more preferably less than 5 mol %, and further preferably less than 3mol %.

The amount of the compound represented by the formula (3) with respectto 100 mol % of the compound represented by the formula (2) isdetermined by liquid chromatography.

The composition containing the sulfonic acid group-containing ethercompound is commonly obtained in the form of an alkaline solution(preferably, an alkaline aqueous solution) in the above method ofproducing the sulfonic acid group-containing ether compound.Accordingly, the composition containing the sulfonic acidgroup-containing ether compound preferably has pH of 10.0 or greater,more preferably 12.0 or greater, further preferably 12.5 or greater, andparticularly preferably 13.0 or greater. In the case where the obtainedcomposition containing the sulfonic acid group-containing ether compoundhas pH of 10.0 or greater, the composition containing the sulfonic acidgroup-containing ether compound has a smaller aging variation in thepolymerizability even when stored in the form of the aqueous solution.Further, in accordance with the application, it is also possible toobtain a neutral or acid composition containing the sulfonic acidgroup-containing ether compound by neutralizing during or after thereaction. The upper limit of the pH value is not particularly limitedand is preferably 14 or less.

In the case where the composition containing the sulfonic acidgroup-containing ether compound contains water, the amount of the wateris preferably 40 parts or more and 99 parts or less with respect to 100parts (by mass) of the composition.

Effect of the Invention

The method of producing the sulfonic acid group-containing ethercompound of the present invention has the configuration as abovedescribed, and therefore, it is possible to easily produce a sulfonicacid group-containing ether compound having a high purity and finepolymerizability at a high yield rate. In addition, the compositioncontaining the sulfonic acid group-containing ether compound of thepresent invention has fewer impurities and fine radical(co)polymerizability. Accordingly, when the compound is used as apolymer material, a polymer excellent in scale inhibition ability can beobtained. Such polymers may be suitably used in chemicals for watertreatment, detergent builders, detergent compositions, dispersants,cleaners, and the like.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention is described in more detail based onexamples, but is not limited only to these examples. All parts are bymass unless otherwise specified, and percentages are by mass unlessotherwise specified, except for the percentages for expressing the yieldrate. The percentages for expressing the yield rate are simplepercentages.

The quantity of the compound such as residual monomers was determined byhigh speed liquid chromatography. The determination was carried outunder the following conditions.

<High Speed Liquid Chromatography>

The quantity was determined under the following conditions with use of“L-7100 type pump”, “L-7300 type column oven”, “L-7200 type autosampler”, and “L-7400 type UV detector” each manufactured by Hitachi,Ltd.

-   Column: “ShodexRSpak DE-413” manufactured by SHOWA DENKO K.K.-   Eluant: 0.1% by weight phosphate solution-   Flow rate: 1 ml/min.-   Calibration curve: A reagent of 40% aqueous solution of    3-allyloxy-2-hydroxy-1-sodium propanesulfonate (manufactured by    Aldrich chemical company Inc.) and 3-allyloxy-1,2-dihydroxypropane    (manufactured by Wako Pure Chemical Industries, Ltd.) were used. The    reagent of 40% aqueous solution of 3-allyloxy-2-hydroxy-1-sodium    propanesulfonate had pH of 6.0. The present chromatography clarified    that the reagent of 40% aqueous solution of    3-allyloxy-2-hydroxy-1-sodium propanesulfonate contains 11.9 mol %    of 3-allyloxy-1,2-dihydroxypropane with respect to 100 mol % of    3-allyloxy-2-hydroxy-1-sodium propanesulfonate.-   Temperature: 40° C.

EXAMPLE 1

Along with the introduction of nitrogen, 0.81 parts of deionized waterand 0.37 parts of a 48% aqueous sodium hydroxide solution were put intoa reaction vessel (made of SUS) having a thermometer, a stirrer, anitrogen inlet tube and a nitrogen outlet provided with a cold trap. Anamount of 2.60 parts of 35% aqueous acid sodium sulfite solution wasadded thereto. At the time, the pH of the reaction liquid was 6.6. Theliquid was heated to 63° C. and 1.0 part of allyl glycidyl ether wasdropped thereto over 120 minutes. At about 60 minutes after the start ofdropping of the allyl glycidyl ether, pH was rapidly changed to strongalkaline. After completing the dropping of the allyl glycidyl ether, thereaction liquid was held to maintain the temperature at 63° C. for 30minutes so that the reaction was completed (a product obtained in thismanner is referred to as “composition (1) containing the sulfonic acidgroup-containing ether compound”). At the completion of the reaction,the pH was 13.9.

In the composition containing the sulfonic acid group-containing ethercompound (1) as a product material, the yield rate of3-allyloxy-2-hydroxy-1-sodium propanesulfonate (sulfonic acidgroup-containing ether compound of the present invention) was 94.9%. Thepercentage of 3-allyloxy-1,2-dihydroxypropane to3-allyloxy-2-hydroxy-1-sodium propanesulfonate (namely, the amount of3-allyloxy-1,2-dihydroxypropane with respect to 100 mol % of3-allyloxy-2-hydroxy-1-sodium propanesulfonate) was 3.9 mol %.

COMPARATIVE EXAMPLE 1

Along with the introduction of nitrogen, 1 part of allyl glycidyl etherwas put into a reaction vessel (made of SUS) having a thermometer, astirrer, a nitrogen inlet tube, and a nitrogen outlet provided with acold trap. An amount of 2.60 parts of 35% aqueous acid sodium sulfitesolution and 1.18 parts of deionized water were added thereto. At thetime, the pH of the reaction liquid was 4.8. After being heated to 90°C., the reaction liquid was reacted at 90° C. for five hours so that thereaction was completed. The yield rate of3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt (sulfonic acidgroup-containing ether compound) (allyl glycidyl ether base) was 84.5%.The amount of 3-allyloxy-1,2-dihydroxypropane with respect to 100 mol %of 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt was 14.9 mol%.

EXAMPLE 2

An amount of 328.5 parts of deionized water was put into a separableflask (made of SUS) provided with a reflux condenser and a stirrer. Thedeionized water was heated while being stirred, so as to be refluxed atthe boiling point (hereinafter, such a state is referred to as “refluxat the boiling point”). In this manner, the deionized water was madeinto a polymerization reaction system. Next, the polymerization reactionsystem under stirring and under reflux at the boiling point was addedwith a mixed aqueous solution (433.6 parts in total) comprising 20.7parts of a 80% aqueous acrylic acid solution (hereinafter, referred toas “80% AA”) and 412.9 parts of 37% aqueous sodium acrylate solution(hereinafter, referred to as “37% SA”), 82.0 parts of a 40% aqueous3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt solution(hereinafter, referred to as “40% HAPS”), 28.7 parts (corresponding to 5parts with respect to 1 mol of monomers in the monomer component) of a35% aqueous hydrogen peroxide solution (hereinafter, referred to as “35%HP”), and 41.5 parts (corresponding to 3.1 parts with respect to 1 molof monomers in the monomer component) of a 15% aqueous sodium persulfatesolution (hereinafter, referred to as “15% NaPS”), and 96.6 parts ofdeionized water. The components were dropped from individual nozzles. Inthis manner, the reaction solution was prepared.

The drop time of the aqueous solutions and the deionized water was setto be 120 minutes for a mixed aqueous solution comprising 80% AA and 37%SA, 90 minutes for 40% HAPS, 120 minutes for 35% HP, and 140 minutes for15% NaPS and for the deionized water. The dropping rate of each of theaqueous solutions and the deionized water was constant and the droppingof each of the aqueous solutions and the deionized water was carried outcontinuously.

After the dropping of the 15% NaPS and the deionized water, the reactionsolution was further held (matured) under reflux at the boiling pointfor 60 minutes so that the polymerization reaction was completed. Theamount of the remaining HAPS after the polymerization was measured to be320 ppm.

Comparison between Example 1 and Comparative Example 1 clarified thatthe yield rate of the sulfonic acid group-containing ether compound wasbetter in the method of the present invention than in a conventionalmethod. In addition, Example 2 clarified that the sulfonic acidgroup-containing ether compound obtained in the method of the presentinvention has excellent polymerizability because it produces lessresidual sulfonic acid group-containing ether compound after thepolymerization.

INDUSTRIAL APPLICABILITY

A composition containing the sulfonic acid group-containing ethercompound of the present invention comprises a highly-pure sulfonic acidgroup-containing ether compound that exerts excellent polymerizabilitywhen the composition is used as a polymer material. In addition, whenthe sulfonic acid group-containing ether compound of the presentinvention is used as a polymerization material, the obtainable polymershows high performance (in particular, scale inhibition ability anddetergency) especially in aqueous applications so as to be suitably usedin chemicals for water treatment, detergent builders, detergentcompositions, dispersants, cleaners, and the like.

1. A composition comprising sulfonic acid group-containing ethercompound represented by the formula (2), wherein the composition has pHof 10 or greater, and the composition comprises, with respect to 100 mol% of the compound represented by the formula (2), less than 10 mol % ofa compound represented by the formula (3):

wherein R¹ represents a single bond, a CH₂ group, or a CH₂CH₂ group, R²represents H, or a CH₃ group, X and Y may be the same as or differentfrom each other and each represent a hydroxy group or a sulfonic acid(salt) group, and at least one of X and Y is a sulfonic acid (salt)group.